Overview

This information is about treatment for skin conditions with a high power, ultraviolet B (UVB) lamp called an excimer lamp. 

Excimer lamp treatment is a new type of phototherapy, which uses ultraviolet light to treat skin conditions. It has recently been approved for use in the Dowling phototherapy unit at Guy's Hospital.

The treatment is used in the private sector but is not widely available in the NHS. We are 1 of only 2 NHS Trusts that uses excimer lamp treatment for phototherapy. The excimer lamp is officially approved (licensed) for use on the skin only and not classified as a laser.

The information covers:

• the benefits of excimer lamp treatment
• the short-term and long-term risks of excimer lamp treatment
• how we prepare for your treatment
• practical tips for when you come to hospital
• your follow-up care

If you have any questions or concerns, please speak to a doctor or nurse caring for you.

About phototherapy

Natural sunlight has been known to help with some skin conditions for thousands of years. 

Phototherapy is a specialised treatment, which you have in the phototherapy unit at your hospital. It is carefully regulated to protect patient safety and has proven to be an effective treatment for many different skin conditions.

The ultraviolet part of the radiation produced by the sun is used in phototherapy. Although it cannot be seen, ultraviolet radiation is an important part of sunlight. It is divided into ultraviolet A (UVA) and ultraviolet B (UVB) wavelengths:

• UVA rays go deeper into the skin than other types of ultraviolet radiation and can cause the skin to tan.
• UVB rays do not go into the skin as deeply but can cause the skin to burn.

In phototherapy, we use carefully calculated amounts (doses) of UVB to reduce the risk of any burning.

About narrowband UVB phototherapy

Narrowband UVB phototherapy is a treatment where a small part of the UVB light spectrum is used to treat a skin condition. Treatment lamps make these special rays, which have anti-inflammatory effects on the skin.

Although the special rays are also present in natural sunlight, narrowband UVB phototherapy is usually more effective than sunlight. This is because harmful and ineffective sunlight rays are filtered out. In this way, we also reduce the risk of burning episodes.

About excimer lamp treatment

Narrowband UVB phototherapy is usually given to the whole body. Excimer lamp treatment is a new type of phototherapy. It uses narrowband UVB rays from a hand-held machine and is designed to treat small, specific areas of skin.

We give you the narrowband UVB rays produced by the excimer lamp through a hand-held wand. This device targets the part of your skin that is different from the surrounding skin.

The treatment gives a dose of narrowband UVB to a specific area of skin, which becomes red. The redness may be harder to notice on brown and black skin. However, the treatment should not cause a blister or sunburn.

Timescale for treatment

In most cases, you have excimer lamp treatment twice a week. 

How many weeks you need excimer lamp treatment depends on your response to this treatment and your specific skin condition. It is usually:

• 5 to 10 weeks for psoriatic plaques
• 8 to 15 weeks for vitiligo
• 10 weeks for alopecia

Benefits of excimer lamp treatment

The hand-held excimer lamp can target specific areas of the body affected by a skin condition. We can then give higher doses of narrowband UVB to these areas. This means that your skin condition should improve faster.

We can use excimer lamp treatment in areas that are difficult to reach with conventional phototherapy, such as the ears.

The aim of the treatment is to clear your skin, although it will not be effective for everyone.

Short-term risks of excimer lamp treatment

Most people cope well with the excimer lamp treatment. The most common effects of this treatment are:

• skin redness (which can be harder to notice on brown and black skin)
• increased pigmentation (tanning) to the treated area

If the doses of narrowband UVB are too high, you could get blistering or crusting of the skin on small treatment areas. In this case, we would stop the treatment for a few sessions until your skin has healed. We would then start your treatment again at a lower dose.

It is also possible to get other side effects on the treated skin areas:

• Your skin may become dry and itchy. You can use moisturiser regularly on the days that you do not have treatment to help with this.
• You may get a spotty, itchy rash (prickly heat). This affects about 1 in 10 people.
• You may get reactive (allergic or intolerant) skin infections. If you have previously had skin infections with herpes simplex virus (such as cold sores, eczema herpeticum or genital herpes), it is important to tell your doctor. The narrowband UVB treatment can make the virus active again. This can cause a burning or stinging pain in the treated areas, followed by pink bumps and small blisters. Your doctor can prescribe antiviral tablets to take during your treatment to reduce the risk of this happening.
• The skin condition being treated may get worse rather than improve. Your doctor explains how likely this is to happen.

Long-term risks of excimer lamp treatment

The long-term risks of having excimer lamp treatment are unknown. They are believed to be similar to the following long-term risks for other types of narrowband UVB phototherapy: 

Skin cancer

People who are exposed to a lot of sunlight have a higher risk of skin cancer. In the UK, about 1 in 10 people get skin cancer.

If we assume that it is the same as sunlight, phototherapy every year during someone's whole life would double the risk of treatable skin cancer. 

Many things can affect this risk. If you do not have your face treated, the risk will be reduced.

You are usually asked to go to your local clinic for a skin cancer review after having more than 500 narrowband UVB treatments.

Photoaging

People who need many treatments may notice skin changes caused by exposure to sunlight. These may include:

• wrinkling
• a change in natural skin tone (skin discolouration)

Skin changes like this are called photoaging. They are similar to those caused by the ageing process or cigarette smoking.